18645171377661 has 12 divisors (see below), whose sum is σ = 27005298179392. Its totient is φ = 12396244728456.

The previous prime is 18645171377659. The next prime is 18645171377687. The reversal of 18645171377661 is 16677317154681.

18645171377661 is a `hidden beast` number, since 1 + 86 + 4 + 517 + 1 + 37 + 7 + 6 + 6 + 1 = 666.

It is not a de Polignac number, because 18645171377661 - 2¹ = 18645171377659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18645171377641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2822456791 + ... + 2822463396.

Almost surely, 2^{18645171377661} is an apocalyptic number.

It is an amenable number.

18645171377661 is a deficient number, since it is larger than the sum of its proper divisors (8360126801731).

18645171377661 is a wasteful number, since it uses less digits than its factorization.

18645171377661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5644920560 (or 5644920557 counting only the distinct ones).

The product of its digits is 35562240, while the sum is 63.

The spelling of 18645171377661 in words is "eighteen trillion, six hundred forty-five billion, one hundred seventy-one million, three hundred seventy-seven thousand, six hundred sixty-one".